The Influence Of Vacuum Interrupter Manufacturing Process Rekindle The Rate Of The Capacitor Bank

At present the re-ignition of vacuum switchgear in capacitor banks is one of the most important tasks need to be solved in domestic. In this paper, the over voltage induced by re-ignition, rules of breakdown in vacuum contact clearance, factors which influence dielectric strength of clearance and characteristics of re-ignition when vacuum switchgear switch capacitor banks are analyzed. The conclusion is that the breakdown of clearance in vacuum interrupter is the direct cause which inducing re-ignition of vacuum circuit-breaker in capacitor banks'switch. Particle breakdown is the essential reason to induce breakdown in clearance of vacuum interrupter, although mechanical characteristic of vacuum circuit-breaker is another factor. The amount of particle influences the re-ignition proportion, and correlate to technical procedure of vacuum interrupter closely .By improving surface condition of parts and one shot seal-off clean room grade, using ultrasonic vapor phase cleaning process, the inner parts of vacuum interrupter get cleaner. Movable particles have been diminished by automatic current ageing, power frequency hi-voltage ageing and dynamic high current ageing. As the dielectric strength of clearance in vacuum interrupter improved, the probability of re-ignition in test drops evidently. The date of experiment shows ,by applying these new techniques , the re-ignition probability of the vacuum switchgear in capacitor banks has decreased from 10.7% to 1.3%.